Trim tab

ABSTRACT

A pair of spaced trim tabs are supported at the bottom of the transom of a boat to extend therebelow when the boat is at rest and when operating at a low speed. Each tab is pivotally supported by a bracket and is urged by a spring to a lowered position below the boat bottom limited to an angular position by a stop engagement between the tabs and the brackets.

United'State s Patent [-ll] 3',5 68,618

72 Inventor William A. Bedford, Jr. [56] References Cited UNITED STATESPATENTS 95 2:2 1969 3,200,782 8/1965 Walden etal..... l l4/66.5

l t l Patented Mar. 9 1971 3,404,651 0/1968 Jensen e a] 14/66 5 [73]Assignee Graham P, Ols Primary Examiner-Andrew H. Farrell S t FlAttorney-Harness, Dickey & Pierce ABSTRACT: A pair of spaced trim tabsare supported at the [54] F bottom of the transom of a boat to extendtherebelow when 7 Chums the boat is at rest and when operating at a lowspeed. Each tab [52] [1.8. CI 114/665 is pivotally supported by abracket and is urged by a spring to a B63b l/22 lowered position belowthe boat bottom limited to an angular Field of Search 114/655 positionby a stop engagement between the tabs and the (P) brackets.

PATENTED MAR BIS?! 2,568, 18

sum 1 n; :11,:

INVE TOR.

PATENTED MAR 9197i 3,558 51 SHEET 2 OF 2 M/Z'dm a 297 215.);

ran/i ran BACKGROUND OF THE INVENTION Reference may be had to B. G.Vandre, US. Pat. No. 2,807,228 issued Sept. 24, 1957 for Adjustable RearFlap For Boats over which the present invention patentablydistinguishes.

SUMMARY OF THE INVENTION The invention pertains to the use of a pair ofhinge tabs having a supporting bracket attachable to the transom of aboat near the bottom thereof to leave a space therebetween for anoutboard motor when applied to a outboard motor driven boat. The tab ishinged to the bracket for pivotal movement relative thereto with aspring provided between the bracket and the tab which urges the tabdownwardly to a predetermined angular position limited by a stopengagement between the tab and the bracket. The spring is so designed asto have the tab effective upon the initial driving of the boat to causethe rear end of the boat to move upwardly out of the water as the bowrises to maintain the boat in substantially horizontal position at alltimes. As the speed of the boat increases the tab will swing upwardly asthe position of the boat is maintained by the planing of the rear end onthe water.

In one form of the invention, the tabs may be further raised upwardly tohave the spring lock the tab in raised position so that it may be backedor dragged over the ground without contact therewith. In one form of theinvention, the bracket and tab are made from a casting and a U-shapedspring with a tapered end is engaged by an extending lip on the tab forproducing a downward urge to the tab against a stop on the bracket witha predetermined force. When the tab is hinged upwardly by the increasedspeed of the boat the resistance to its movement is decreased due to thechange of the contact point of the tab with the spring so that littleresistance is offered to the movement of the boat by the tab.

In a second form of the invention, the bracket and tab are made fromstampings which are hinged together with a coil spring on the connectingpintle having extending ends one of which engages the bracket the otherof which engages the tab to urge it downwardly. A projecting lip on thetab engages the bracket when the tab is disposed in a desired angularposition below the boat.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a view of the rear end of aboat showing the transom thereof having a pair of spaced bracketssecured near the bottom with hinged tabs which embody features of thepresent invention;

FIG. 2 is an enlarged broken view of the structure illustrated in FIG.1, taken within the circle 2 thereof;

FIG. 3 is a sectional view of the structure illustrated in FIG. 2, takenon the line 3-3 thereof, with the tabs disposed in downward position;

FIG. 4 is a view of the structure illustrated in FIG. 3, with the tabshown in raised locked position;

FIG. 5 is a view of structure, similar to that illustrated in FIG. 3,showing another form of the invention with the tabs in downward angularposition relative to the transom;

FIG. '5 is a view of the structure illustrated in FIG. 5, with the tabillustrated in raised position;

FIG. 7 is aview of the structure illustrated in FIG. 5, as viewed fromthe point 7 thereof; and

FIG. II is a broken sectional view of the structure illustrated in FIG.7, taken on the line 3-3 thereof.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring specifically to FIGS.1 to d inclusive, a boat 11 has a transom 12 at the rear end on which apair of spaced tab structures 33 are supported near the bottom edgethereof. Each tab structure embodies a bracket I45 having right angleflanges 15 and 16, the latter of which supports spaced sleeves 17 whichfunctions as a hinge leaf. The sleeves 17 have a bottom extension 18which forms a stop face 19. A tab 21 has a rectangular blade 22 and apair of sleeves 23 which are simiiar to the sleeves 17 between which thesleeves 23 are hingedly supported on a hinge pin 24. A U-shaped spring25 made of stainless steel, bronze, and other rust-resisting material,has a flange 26 containing a pair of apertures 27 which align with apair of apertures 28 in the flange 15 of the bracket 14 and throughwhich a pair of screws 29 extend for securing the spring to the centralpart of the bracket. The screws 29 support the bracket 14 which isfurther supported by a pair of screws 30 which extend through aperturesprovided near the ends thereof. An unsecured flange 31 of the U-shapedspring 25 forms the deflectable portion thereof and said edges 32 of thespring are tapered to change the spring rate of the flange 31. The tab21 has a lip 33 disposed between the hinge sleeves 23 in position toengage the flange 31 of the spring 25. The pressure point of the lip 33engages the maximum resistance point of the flange 31 and as the lipmoves from the resistance point the resistance to hinging of the tab 21reduces so that after the tab 21 starts to move, the resistance tomovement progressively decreases. The frictional drag between the lip 33and the flange 31 of the spring functions as a damper to prevent anyundue vibration of the trim tabs in any of its positions. in FIG. 3, thetab 21 is shown in its down position into which it is urged by theU-shaped spring 25 with the forward edge of the tab abutted against thestop faces 19 of the sleeves 17 of the brackets 14. As the boat ispropelled forwardly, the bow will move out of the water and the transomend will be raised by the tabs to maintain the boat in a substantiallyhorizontal position at all times. As the speed increases the tabs willhinge upwardly to the rear maintaining the boat in parallel to itsstarting position as it planes over the water.

Another feature of the tab arrangement is that illustrated in FIG. 4where the tabs are manually pulled upwardly into locked position withthe end of the flange 31 of the spring extending over the lip 33 formaintaining the tab in raised position. This permits the boat to be slidbackwardly, forwardly or sidewardly over the ground without any damageto the tab structure. The tabs provide the further feature of preventingthe rear end of the boat from rapidly sinking when the throttle isreduced. The boat will not sink or drag down in the stern at reducedspeed but will settle down in a level condition since the tabs will movedownwardly to the position illustrated in FIG. 3 and provide lift forthe stern so that the sinking thereof at the rear is avoided. The tabsproduce the planing of the boat. with less effort and there is lessviolent reaction to rapid changes in the throttle and will plane atsubstantially less than what would be considered a normal planing speed.After this speed is reached there is no drag due to the presence of thetabs.

Similar structure is illustrated in FIGS. 5 to 3, wherein a tabstructure 35 has a bracket 36 and a tab 37 formed as stampings. Thebracket 36 is in the nature of a plate having hinged sleeves 33 at theends between which hinge sleeves 39 on the tab 37 are secured by a hingepin 41. The bracket 36 is secured in spaced relation to each other atthe bottom of the transom 12 by a plurality of screws 42. The spacebetween the sleeves 39 is occupied by a coil spring 43 secured over thehinge pin 41. One end of the spring 43 has an arm 45 which engages thebracket 36, the opposite end having an arm as which engages the tab 37to urge it downwardly. At the central portion the tab 37, in the area ofthe spring 453, a flange 47 is bent downwardly which moves into stopengagement with the bracket 36 when disposed in downward angularrelation to the transom 12. as illustrated in FIGS. 5 and S. In FIG. .6,the tab 37 is illustrated in raised position and an arcuate dotted lineextension 47 on the outer end of the tab provides a tangentialengagement with the water rather than an edge engagement therewith. Thestructure of FIGS. 5 to S functions in the same manner as that pointedout above with regards to the structure of FIGS. 1 to i with theexception that the structure of FIGS. 5

to 3 lacks the locking feature for the tab when the tab is manuallyurged to its maximum upwardly hinged position.

lclaim:

1. 'In a trim tab for a boat, a bracket securable to the lower bottomportion of the boat transom, a tab pivoted to said bracket, and metalspring means of U-shape having a fixed and a free leg, the free legbeing located between the bracket and tab providing direct engagementwith the tab for urging said tab downwardly and for resisting the upwardpivotal movement of the tab with a predetermined force.

2. In a trim tab for a boat as recited in claim 1, wherein stop meansare provided between the tab and bracket for limiting the downwardhinging movement of the tab by said spring means.

3. In a trim tab for a boat as recited in claim 2, wherein the brackethas sleeves at the ends and wherein the tab has sleeve means and aprojecting lip disposable between the bracket sleeves, said lip beingengaged by the free leg of said spring means.

4. In a trim tab as recited in claim 3, wherein the spring means is madefrom a strip of spring steel with one leg supported on the bracket andthe opposite leg extending rearwardly in spaced relation thereto inengagement with said lip.

5. In a trim tab as recited in claim 4, wherein the bottom edge of therearwardly extending free leg engages the top of the lip for retainingthe tab in maximum upward position when manually moved thereto.

6. In a trim tab as recited in claim 5, wherein the side edges of theU-shaped spring means taper toward each other to change the spring rateof the free leg.

7. In a trim tab as recited in claim 6, wherein a maximum resistance isprovided between the free leg of the spring means and the lip when thetab engages the stop means which resistance reduces as the tab pivotsupwardly.

1. In a trim tab for a boat, a bracket securable to the lower bottomportion of the boat transom, a tab pivoted to said bracket, and metalspring means of U-shape having a fixed and a free leg, the free legbeing located between the bracket and tab providing direct engagementwith the tab for urging said tab downwardly and for resisting the upwardpivotal movement of the tab with a predetermined force.
 2. In a trim tabfor a boat as recited in claim 1, wherein stop means are providedbetween the tab and bracket for limiting the downward hinging movementof the tab by said spring means.
 3. In a trim tab for a boat as recitedin claim 2, wherein the bracket has sleeves at the ends and wherein thetab has sleeve means and a projecting lip disposable between the bracketsleeves, said lip being engaged by the free leg of said spring means. 4.In a trim tab as recited in claim 3, wherein the spring means is madefrom a strip of spring steel with one leg supported on the bracket andthe opposite leg extending rearwardly in spaced relation thereto inengagement with said lip.
 5. In a trim tab as recited in claim 4,wherein the bottom edge of the rearwardly extending free leg engages thetop of the lip for retaining the tab in maximum upward position whenmanually moved thereto.
 6. In a trim tab as recited in claim 5, whereinthe side edges of the U-shaped spring means taper toward each other tochange the spring rate of the free leg.
 7. In a trim tab as recited inclaim 6, wherein a maximum resistance is provided between the free legof the spring means and the lip when the tab engages the stop meanswhich resistance reduces as the tab pivots upwardly.